Chronic lymphocytic leukemia (CLL) is characterized by a predominant humoral immune deficiency predisposing the patients to infections. Oxidative stress leads to an increased immunoglobulin k light chain production in B cells and contributes to the antibodies' deficiency and hypogammaglobulinemia. Aim of the Study. To evaluate the global oxidative status in patients with CLL and to determine whether the administration of antioxidants decreases complications due to infections. Patients and Method. We studied 84 patients with CLL stratified by Binet staging. Free oxygen radicals and antioxidant status were determined by the FORT and FORD test, respectively, at diagnosis and in the presence of infections. The patients were distributed in two groups: group A, treated only with antileukemic treatment, and group B, treated with antileukemic treatment and antioxidants. Results. By FORD and FORT assay, all patients had at diagnosis a low antioxidant capacity, and high levels of hydroperoxides. Infectious complications were more frequent in group A (B/C stages of disease) than in group B. Administrations of antioxidants stimulated the immune response and decreased infectious complications in CLL. Conclusions. Administrations of antioxidants and a healthy life style may improve the quality of life of patients with CLL and reduce the risk of infectious complications.